X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/38b78e8763833fee8b41ecaf7586558e9b60d254..79766c36e3ccde29b7123b203dcf47fbb4864d73:/src/utilities.lisp

diff --git a/src/utilities.lisp b/src/utilities.lisp
index 4935f8b..bdcdf80 100644
--- a/src/utilities.lisp
+++ b/src/utilities.lisp
@@ -651,16 +651,17 @@
 						   (symbol-name name) "-")))
 			   cat-names))
 	 (items-var (gensym "ITEMS-")))
-    `(let ((,items-var ,items)
-	   ,@(mapcar (lambda (cat-var) (list cat-var nil)) cat-vars))
-       (dolist (,itemvar ,items-var)
-	 (let* ,bind
-	   (cond ,@(mapcar (lambda (cat-match-form cat-var)
-			     `(,cat-match-form
-			       (push ,itemvar ,cat-var)))
-			   cat-match-forms cat-vars)
-		 ,@(and (not (member t cat-match-forms))
-			`((t (error "Failed to categorize ~A" ,itemvar)))))))
+    `(let (,@(mapcar (lambda (cat-var) (list cat-var nil)) cat-vars))
+       (let ((,items-var ,items))
+	 (dolist (,itemvar ,items-var)
+	   (let* ,bind
+	     (cond ,@(mapcar (lambda (cat-match-form cat-var)
+			       `(,cat-match-form
+				 (push ,itemvar ,cat-var)))
+			     cat-match-forms cat-vars)
+		   ,@(and (not (member t cat-match-forms))
+			  `((t (error "Failed to categorize ~A"
+				      ,itemvar))))))))
        (let ,(mapcar (lambda (name var)
 		       `(,name (nreverse ,var)))
 		     cat-names cat-vars)
@@ -1038,6 +1039,61 @@
 					    condition)))
 	 arguments))
 
+(export '(enclosing-condition enclosed-condition))
+(define-condition enclosing-condition (condition)
+  ((%enclosed-condition :initarg :condition :type condition
+			:reader enclosed-condition))
+  (:documentation
+   "A condition which encloses another condition
+
+   This is useful if one wants to attach additional information to an
+   existing condition.  The enclosed condition can be obtained using the
+   `enclosed-condition' function.")
+  (:report (lambda (condition stream)
+	     (princ (enclosed-condition condition) stream))))
+
+(export 'information)
+(define-condition information (condition)
+  ())
+
+(export 'simple-information)
+(define-condition simple-information (simple-condition information)
+  ())
+
+(export 'info)
+(defun info (datum &rest arguments)
+  "Report some useful diagnostic information.
+
+   Establish a simple restart named `noted', and signal the condition of type
+   `information' designated by DATUM and ARGUMENTS.  Return non-nil if the
+   restart was invoked, otherwise nil."
+  (restart-case
+      (signal (designated-condition 'simple-information datum arguments))
+    (noted () :report "Noted." t)))
+
+(export 'noted)
+(defun noted (&optional condition)
+  "Invoke the `noted' restart, possibly associated with the given CONDITION."
+  (invoke-associated-restart 'noted condition))
+
+(export 'promiscuous-cerror)
+(defun promiscuous-cerror (continue-string datum &rest arguments)
+  "Like standard `cerror', but robust against sneaky changes of conditions.
+
+   It seems that `cerror' (well, at least the version in SBCL) is careful
+   to limit its restart to the specific condition it signalled.  But that's
+   annoying, because `sod-parser:with-default-error-location' substitutes
+   different conditions carrying the error-location information."
+  (restart-case (apply #'error datum arguments)
+    (continue ()
+      :report (lambda (stream)
+		(apply #'format stream continue-string datum arguments))
+      nil)))
+
+(export 'cerror*)
+(defun cerror* (datum &rest arguments)
+  (apply #'promiscuous-cerror "Continue" datum arguments))
+
 ;;;--------------------------------------------------------------------------
 ;;; CLOS hacking.